The recent UN alert that drought in the Sahel threatens 15 million lives is a harbinger of things to come.

In the next twenty years, global demand for fresh water will vastly
outstrip reliable supply in many parts of the world. Thanks to
population growth and agricultural intensification, humanity is drawing
more heavily than ever on shared river basins and underground aquifers.
Meanwhile, global warming is projected to exacerbate shortages in
already water-stressed regions, even as it accelerates the rapid melting
of glaciers and snow cover upon which a billion people depend for their
ultimate source of water.

This sobering message emerges from the first U.S. Intelligence Community Assessment of Global Water Security.
The document predicts that by 2030 humanity's "annual global water
requirements" will exceed "current sustainable water supplies" by forty
percent. Absent major policy interventions, water insecurity will
generate widespread social and political instability and could even
contribute to state failure in regions important to U.S. national
security. (Look here for a webcast from the Woodrow Wilson Center of experts and U.S. government officials discussing the findings.)

The simultaneous ubiquity and scarcity of water is one of Earth's
little ironies. Globally, 97.5 percent of H2O is contained in world's
oceans. Of the planet's "fresh" water (the residual 2.5%), more than
two-thirds is encased in ice packs and glaciers, particularly in
Antarctica and Greenland, another thirty percent in groundwater, and
almost one percent in high latitude permafrost. That leaves us with
about 0.4 percent of global fresh water to account for: about two-thirds
of that is contained in freshwater lakes, with the rest distributed
among soil moisture (12 percent), the atmosphere (9.5 percent), wetlands
(8.5 percent), rivers (1.5 percent) and vegetation (1 percent).

The need for reliable sources of fresh water is as old as our
species, of course. What is new today is the combustible combination of
surging global demand for increasingly scarce fresh water in certain
volatile regions of poor governance. Several factors are driving this
trend.

Demographic pressure: By 2025, the world's
population will swell from seven to nearly eight billion. The vast
majority of this increase will occur in the developing world,
particularly Africa. In rapidly expanding urban centers, demand for
fresh water will rise for personal consumption, sanitation, industry,
and hydroelectric use.

Declining Fresh H2O supplies: According to Global Water Security,
"one third of the world's population will live near water basins where
the water deficit will be larger than 50 percent by 2030." Many regions
that are already experiencing water stress will become "extremely more
stressed" or even "exceptionally more stressed." In some areas, rapid
depletion of underground aquifers will be the culprit. In others it will
be reductions in meltwater as glaciers recede. In the Andes, hundreds
of glaciers will simply disappear in coming decades, eliminating dry
season water supplies. Similar, though more gradual, dynamics will be at
play in the Himalayas, sometimes referred to as the world's "third
pole".

Changing dietary preferences: Meanwhile, the global middle class will surge from 1.8 to 4.9 billion by 2030. Wealthier populations will consume more meat,
requiring a shift to more energy and water-intensive agriculture
focusing on the raising of livestock and feed grain. Already today, some
93 percent of fresh water consumed is devoted to agriculture (from a
combination of riverine, lake, and groundwater sources). Without massive
behavioral changes, changing land use and food consumption patterns
will place even greater pressures on fresh water resources.

Poor Water Management: Adapting to a new
era of water scarcity will require enormous investments in integrated
water management, particularly in the developing world. This would
include improving agricultural efficiency through new irrigation systems
and drought-resistant crops; renovating infrastructure to reduce urban
"water leakage" (which averages 30-50 percent in many cities);
clarifying rights to the use of subterranean, riverine, and lacustrine
water resources; and introducing pricing mechanisms that reflect the
true economic value of water--admittedly a politically volatile step in
societies where free (or cheap) access to water is viewed as an
inherent, longstanding right.

Significantly, the intelligence community does not predict
that increased competition for water resources will, by itself, be a source of
violent conflict--a finding borne out by a rich body of research. And yet the same document warns that
water stress may well "contribute to the risk of instability and state
failure," particularly "when combined with poverty, social tensions,
environmental degradation, ineffectual leadership, and weak political
institutions." The accompanying map makes clear that many of the countries
likely to be hardest hit are fragile and/or authoritarian states located within
the broad arc of instability encompassing North Africa, the Horn, the Arabian
Peninsula, and southwest, central, and south Asia. In other words, states least
able to cope.

Regional tensions over shared river basins will also rise.
States will use diplomatic and other leverage to preserve their water
interests, and "upstream" states will be tempted to use water as a
diplomatic weapon, including by threatening to impede flow. Nonstate actors,
notably terrorists and other extremists, may also seek to sabotage dams and
other infrastructure.

Regional stability and peace, therefore, increasingly depend
on effective management of the world's 263 shared international water basins.
"Today, water basin agreements often do not exist or are inadequate."
Analyzing the current capacity to manage seven major water basins, Global Water
Security assesses mechanisms to govern the Brahmaputra and Amu Darya to be
"inadequate," and those governing the Tigris-Euphrates, the Nile, and
the Mekong as "limited." (The Indus and the Jordan rivers earn a
higher, "moderate" score.)

By revealing the scale and consequences of global water
crisis, the intelligence community has performed a great service. But the
policy response to date has been just a drop in the bucket.

This article
originally appeared at CFR.org,
an Atlantic partner site.

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